Repetitions

Memory limit: 32 MB

A sequence of words over alphabet is given. The length of longest word occuring as a coherent fragment in every word given is to be found.

Task

Write a program which:

• reads the sequence of words from the standard input,
• counts the length of the longest word occuring as a coherent fragment in every word given,
• writes the result to the standard output.

Input

In the first line of the standard input there is an integer , where is the number of words. In each of the next lines there is one word formed from small letters of English alphabet . The length of each word is at least , but not greater than .

Output

The text of standard output should consist of exactly one line containing a single integer equal to the length of the longest word occuring as the coherent fragment in every word given.

Example

For the input data:

3
abcb
bca
acbc

the correct result is:

2

Task author: Adam Malinowski.